Response time to text versus e-mail?

Ok – am I just an impatient ninny or do others expect a faster response to a text than an e-mail? Usually, with an e-mail, I know the person might not receive it right away or may just need processing time. But with some friends, whom I know keep their cellphone nearby, I am kind of thrown when they don’t respond to a text within a few hours. (Maybe it is the ones I am most insecure about.) What about you?